Phospholipid Docosahexaenoic Acid Research Articles

Knockdown of Placental Major Facilitator Superfamily Domain Containing 2a in Pregnant Mice Reduces Fetal Brain Growth and Phospholipid Docosahexaenoic Acid Content.

Docosahexaenoic acid (DHA) is an n-3 long chain polyunsaturated fatty acid critical for fetal brain development that is transported to the fetus from the mother by the placenta. The lysophosphatidylcholine (LPC) transporter, Major Facilitator Superfamily Domain Containing 2a (MFSD2a), is localized in the basal plasma membrane of the syncytiotrophoblast of the human placenta, and MFSD2a expression correlates with umbilical cord blood LPC-DHA levels in human pregnancy. We hypothesized that placenta-specific knockdown of MFSD2a in pregnant mice reduces phospholipid DHA accumulation in the fetal brain. Mouse blastocysts (E3.5) were transduced with an EGFP-expressing lentivirus containing either an shRNA targeting MFSD2a or a non-coding sequence (SCR), then transferred to pseudopregnant females. At E18.5, fetuses were weighed and their placenta, brain, liver and plasma were collected. MFSD2a mRNA expression was determined by qPCR in the brain, liver and placenta and phospholipid DHA was quantified by LC-MS/MS. MFSD2a-targeting shRNA reduced placental mRNA MFSD2a expression by 38% at E18.5 (n = 45, p < 0.008) compared with SCR controls. MFSD2a expression in the fetal brain and liver were unchanged. Fetal brain weight was reduced by 13% (p = 0.006). Body weight, placenta and liver weights were unaffected. Fetal brain phosphatidyl choline and phosphatidyl ethanolamine DHA content was lower in fetuses with placenta-specific MFSD2a knockdown. Placenta-specific reduction in expression of the LPC-DHA transporter MFSD2a resulted in reduced fetal brain weight and lower phospholipid DHA content in the fetal brain. These data provide mechanistic evidence that placental MFSD2a mediates maternal-fetal transfer of LPC-DHA, which is critical for brain growth.

Dynamics of Docosahexaenoic Acid Utilization by Mouse Peritoneal Macrophages.

In this work, the incorporation of docosahexaenoic acid (DHA) in mouse resident peritoneal macrophages and its redistribution within the various phospholipid classes were investigated. Choline glycerophospholipids (PC) behaved as the major initial acceptors of DHA. Prolonged incubation with the fatty acid resulted in the transfer of DHA from PC to ethanolamine glycerophospholipids (PE), reflecting phospholipid remodeling. This process resulted in the cells containing similar amounts of DHA in PC and PE in the resting state. Mass spectrometry-based lipidomic analyses of phospholipid molecular species indicated a marked abundance of DHA in ether phospholipids. Stimulation of the macrophages with yeast-derived zymosan resulted in significant decreases in the levels of all DHA-containing PC and PI species; however, no PE or PS molecular species were found to decrease. In contrast, the levels of an unusual DHA-containing species, namely PI(20:4/22:6), which was barely present in resting cells, were found to markedly increase under zymosan stimulation. The levels of this phospholipid also significantly increased when the calcium-ionophore A23187 or platelet-activating factor were used instead of zymosan to stimulate the macrophages. The study of the route involved in the synthesis of PI(20:4/22:6) suggested that this species is produced through deacylation/reacylation reactions. These results define the increases in PI(20:4/22:6) as a novel lipid metabolic marker of mouse macrophage activation, and provide novel information to understand the regulation of phospholipid fatty acid turnover in activated macrophages.

DHA, nutrient intake, and maternal characteristics as predictors of pregnancy outcomes in a randomised clinical trial of DHA supplementation

To investigate the relationships among docosahexaenoic acid (DHA) intake, nutrient intake, and maternal characteristics on pregnancy outcomes in a phase III randomised clinical trial designed to determine the effect of a DHA dose of 1000mg/day compared to 200mg/day on early preterm birth (<34 weeks gestation). A secondary aim of the phase III randomised trial was to explore the relationships among pregnancy outcomes (maternal red blood cell phospholipid (RBC-PL) DHA at delivery, preterm birth, gestational age at delivery, labor type, birth anthropometric measures, low birth weight, gestational diabetes, pre-eclampsia, and admission to a neonatal intensive care unit) in participants (n=1100). We used Bayesian multiple imputation and linear and logistic regression models to conduct an analysis of five general classes of predictor variables collected during the trial: a) DHA intake, b) nutrient intake from food and supplements, c) environmental exposure to tobacco and alcohol, d) maternal demographics, and e) maternal medical history. DHA supplementation lowered the risk of preterm birth and NICU admission, and increased gestation and birth weight as observed in the primary analysis. Higher maternal RBC-PL-DHA at delivery was associated with DHA supplementation and formal education of a bachelor's degree or higher. DHA supplementation and maternal age were associated with a higher risk of gestational diabetes. Total vitamin A intake was associated with longer gestation, while fructose and intake of the long chain omega-6 fatty acid, arachidonic acid, were associated with shorter gestation. Risk of preterm birth was associated with a history of low birth weight, preterm birth, pre-eclampsia, and NICU admission. Bayesian models provide a comprehensive approach to relationships among DHA intake, nutrient intake, maternal characteristics, and pregnancy outcomes. We observed previously unreported relationships between gestation duration and fructose, vitamin A, and arachidonic acid that could be the basis for future research. ClinicalTrials.gov (NCT02626299); December 10, 2015.

Long-Chain Polyunsaturated Fatty Acids n-3 (n-3 LC-PUFA) as Phospholipids or Triglycerides Influence on Epinephelus marginatus Juvenile Fatty Acid Profile and Liver Morphophysiology.

Simple SummaryFish feeding is responsible for almost 60% of the total cost of marine fish production, so nutritional studies are always in demand. Dusky grouper is a promising species for aquaculture, but studies of the species’ nutrition are still lacking. The present study investigated the effects of fatty acids, provided as different lipid classes in four different diets, for Epinephelus marginatus fingerlings and evaluated their physiological and morphological responses in order to provide new insights about grouper nutrition. The fatty acids, provided as different lipid classes, modified the physiological and morphological responses of E. marginatus, showing that the inclusion of these lipids as different classes should be considered in order to obtain better results in terms of fish fillet quality. These results provided valuable insights into the nutrition and physiology of dusky groupers, helping to pave the way for the establishment of this fish species as a produced species worldwide.Phospholipids (PL) are membrane components composed of fatty acids (FA), while triglycerides (TG) are a main source of energy and essential FA. Polyunsaturated FA (PUFA), such as docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), are essential for marine carnivorous fish; thus, an 8-week experiment was performed to evaluate the influence of DHA and EPA, provided as PL and TG, on the morphophysiology of Epinephelus marginatus juveniles. A basal diet was manufactured, and DHA and EPA in PL form (PL1—low amount PL2—high amount) and TG form (TG1—low amount; TG2—high amount) were added. Dusky grouper juveniles were equally distributed in 12 tanks of 20 animals each, and liver and muscle were sampled for metabolic analysis. The total hepatic lipids in PL1 and PL2 were higher when compared to the initial, TG1 and TG2 groups. Total lipids in muscle were higher in PL2 and TG1 than PL1 and TG2, respectively. Diets rich in DHA and EPA in PL and TG resulted in higher deposition of these FA in the muscle polar fraction. However, fish fed diets containing lower amounts of DHA and EPA in PL and TG stored those in the muscle neutral fraction and liver, centralizing the storage of DHA and EPA.

Longitudinal Associations of Plasma Phospholipid Fatty Acids in Pregnancy with Neonatal Anthropometry: Results from the NICHD Fetal Growth Studies-Singleton Cohort.

Despite increasing interest in the health effects of polyunsaturated FAs (PUFAs), their roles in fetal and neonatal growth remain understudied. Within the NICHD Fetal Growth Studies—Singleton Cohort, we prospectively investigated the associations of individual and subclasses of plasma phospholipid PUFAs at gestational weeks (GW) 10–14, 15–26, 23–31, and 33–39 with neonatal anthropometric measures as surrogates for fetal growth among 107 women with gestational diabetes mellitus (GDM) and 214 non-GDM controls. Multivariable weighted linear regression models estimated the associations between plasma phospholipid PUFAs and neonatal anthropometric measures. Adjusted beta coefficients for phospholipid docosahexaenoic acid (DHA) per standard deviation (SD) increase at GW 23–31 in association with birthweight z-score, neonatal length, and neonatal fat mass were 0.25 (95% CI: 0.08–0.41), 0.57 (0.11–1.03) cm, and 54.99 (23.57–86.42) g, respectively; all false discovery rates (FDRs) < 0.05. Estimated Δ5-desaturase activity per SD increase at GW 33–39 but not at other time points was positively associated with birthweight z-score: 0.29 (95% CI: 0.08–0.33); neonatal length: 0.61 (0.29–0.94) cm; and neonatal fat mass: 32.59 (8.21–56.96) g; all FDRs < 0.05. Longitudinal analysis showed consistent results. Our findings suggest that mid-to-late pregnancy presented as critical windows for primarily diet-derived DHA and Δ5-desaturase activity in relation to neonatal anthropometric measures.

Validation of an abbreviated food frequency questionnaire for estimating DHA intake of pregnant women in the United States

Docosahexaenoic acid (DHA) intake was estimated in pregnant women between 12- and 20-weeks’ gestation using the National Cancer Institute's (NCI) Diet History Questionnaire-II (DHQ-II) and a 7-question screener designed to capture DHA intake (DHA Food Frequency Questionnaire, DHA-FFQ). Results from both methods were compared to red blood cell phospholipid DHA (RBC-DHA) weight percent of total fatty acids. DHA intake from the DHA-FFQ was more highly correlated with RBC-DHA (rs=0.528) than the DHQ-II (rs=0.352). Moreover, the DHA-FFQ allowed us to obtain reliable intake data from 1355 of 1400 participants. The DHQ-II provided reliable intake for only 847 of 1400, because many participants only partially completed it and it was not validated for Hispanic participants. Maternal age, parity, and socioeconomic status (SES) were also significant predictors of RBC-DHA. When included with estimated intake from the DHA-FFQ, the model accounted for 36% of the variation in RBC-DHA.

Dietary Alpha-Linolenic Acid Supports High Retinal DHA Levels.

The retina requires docosahexaenoic acid (DHA) for optimal function. Alpha-linolenic acid (ALA) and DHA are dietary sources of retinal DHA. This research investigated optimizing retinal DHA using dietary ALA. Previous research identified 19% DHA in retinal phospholipids was associated with optimal retinal function in guinea pigs. Pregnant guinea pigs were fed dietary ALA from 2.8% to 17.3% of diet fatty acids, at a constant level of linoleic acid (LA) of 18% for the last one third of gestation and retinal DHA levels were assessed in 3-week-old offspring maintained on the same diets as their mothers. Retinal DHA increased in a linear fashion with the maximum on the diet with LA:ALA of 1:1. Feeding diets with LA:ALA of 1:1 during pregnancy and assessing retinal DHA in 3-week-old offspring was associated with optimized retinal DHA levels. We speculate that the current intakes of ALA in human diets, especially in relation to LA intakes, are inadequate to support high DHA levels in the retina.

Entorhinal thickness: A marker of DHA supplementation efficacy?

AbstractBackgroundThe entorhinal cortex (ERC) area in the brain is affected early in AD, particularly among APOE4 carriers. We previously reported a positive association between plasma phospholipid docosahexaenoic acid (DHA) levels and the ERC thickness in the Aging Brain Program. We hypothesize that increases in plasma DHA after high‐dose DHA supplementation protects against thinning of the ERC when started before cognitive impairment including in APOE4 carriers, and that ERC thickness can be a useful marker for DHA supplementation efficacy.MethodWe examined the effect of DHA treatment and association of plasma DHA species on the changes in the ERC area in the DHA Brain Delivery Pilot Trial (NCT02541929). T1‐weighted MRI scans were collected at 3T and FreeSurfer software was used to segment the ERC thickness. Total DHA, DHA in phosphatidylcholine (PC), lysophosphatidylcholine (LPC), and phosphatidylethanolamine (PE) were measured in plasma together with Red blood cell (RBC) DHA levels before and after randomization to 2 grams of triglyceride DHA per day vs placebo over 6 months (n=28). Participants were all cognitively normal, consumed less than 200 mg of DHA per day, and were stratified by APOE4 genotype before randomization.ResultDHA treatment, adjusted for APOE4, was associated with a significant increase in ERC area thickness compared with placebo (mean group difference in ERC change (95% CI) 0.161 (0.003, 0.319), p=0.046). Among DHA subspecies measured, greater increase in plasma PC DHA levels after supplementation was significantly correlated with greater ERC area (mean ERC change per SD of PC DHA=0.103, p=0.011). The association persisted after adjusting for APOE4 status (mean ERC change per SD of PC DHA=0.109, p=0.007), indicating that the effect was independent of APOE4 status.ConclusionThese preliminary findings support a protective effect of high dose DHA in preserving the ERC thickness, including among APOE4 carriers. This finding supports early intervention, before the onset of cognitive impairment, with high dose DHA supplementation in individuals at risk of cognitive decline. PREVENTE4 trial (NCT03613844) is ongoing to help understand whether high dose DHA can prevent cognitive decline in individuals at increased risk of AD.HNY is supported by AA NIRG‐15‐361854, R01AG054434, R21AG056518, ADDF GC‐201711‐2014197.

Long Chain Polyunsaturated Fatty Acids Docosahexaenoic Acid and Arachidonic Acid Supplementation in the Suckling and the Post-weaning Diet Influences the Immune System Development of T Helper Type-2 Bias Brown Norway Rat Offspring.

Background: Dietary long chain polyunsaturated fatty acids (LCPUFA) such as arachidonic acid (ARA) and docosahexaenoic acid (DHA) play an important role in the development of the infant immune system. The role of LCPUFA in the T helper type 2 (Th2) biased immune system is unknown. We aimed to understand the effect of feeding LCPUFA during suckling and post-weaning on immune system development in Th2 bias Brown Norway rat offspring.Methods: Brown Norway dams were randomly assigned to nutritionally adequate maternal diet throughout the suckling period (0–3 weeks), namely, control diet (0% ARA, 0% DHA; n= 8) or ARA + DHA (0.45% ARA, 0.8% DHA; n = 10). At 3 weeks, offspring from each maternal diet group were randomized to either a control (0% ARA, 0% DHA; n = 19) or ARA+DHA post-weaning (0.5% ARA, 0.5% DHA; n = 18) diet. At 8 weeks, offspring were killed, and tissues were collected for immune cell function and fatty acid composition analyses.Results: ARA + DHA maternal diet resulted in higher (p < 0.05) DHA composition in breast milk (4×) without changing ARA levels. This resulted in more mature adaptive immune cells in spleen [T regulatory (Treg) cells and B cells], mesenteric lymph nodes (MLN, lower CD45RA+), and Peyer's patches (PP; higher IgG+, B cells) in the ARA+DHA group offspring at 8 weeks. ARA+DHA post-weaning diet (3–8 weeks) resulted in 2 × higher DHA in splenocyte phospholipids compared to control. This also resulted in higher Th1 cytokines, ~50% higher TNF-α and IFNγ, by PMAi stimulated splenocytes ex vivo, with no differences in Th2 cytokines (IL-4, IL-13, and IL-10) compared to controls.Conclusion: Feeding dams a diet higher in DHA during the suckling period resulted in adaptive immune cell maturation in offspring at 8 weeks. Providing ARA and DHA during the post-weaning period in a Th2 biased Brown Norway offspring model may support Th1 biased immune response development, which could be associated with a lower risk of developing atopic diseases.

Health benefits of docosahexaenoic acid and its bioavailability: A review.

Docosahexaenoic acid (DHA) is the predominant omega‐3 long‐chain polyunsaturated fatty acid found in human brain and eyes. There are a number of studies in the literature showing the health benefits of DHA. It is critical throughout all life stages from the need for fetal development, the prevention of preterm birth, and the prevention of cardiovascular disease to the improvements in the cognitive function and the eye health of adults and elderly. These benefits might be related to the modulation of gut microbiota by DHA. In addition, there are some discrepancies in the literature regarding certain health benefits of DHA, and this review is intended to explore and understand these discrepancies. Besides the variations in the DHA contents of different supplement sources, bioavailability is crucial for the efficacy of DHA supplements, which depends on several factors. For example, DHA in phospholipid and triglyceride forms are more readily to be absorbed by the body than that in ethyl ester form. In addition, dietary lipids in meals and emulsification of DHA oil can increase the bioavailability of DHA. Estrogens stimulated the biosynthesis of DHA, whereas testosterone stimulus induced a decrease in DHA. The roles of DHA through human lifespan, the sources, and its recommended daily intake in different countries are also discussed to provide a better understanding of the importance of this review.

Effect of increased levels of dietary α-linolenic acid on the n-3 PUFA bioavailability and oxidative stress in rat.

We investigated the impact of increased alpha-linolenic acid (ALA) dietary levels on its plasma bioavailability and its bioconversion in n-3 long chain poly unsaturated fatty acids during a 60-d kinetics and the oxidative stress potentially associated. Rats were submitted to a normolipidic diet providing 0, 3, 10 and 24% ALA of dietary lipids for 0, 15, 30 and 60 days. The lipid peroxidation and oxidative stress (nitric oxide (NO) contents and catalase (CAT), superoxide dismutase (SOD), gluthation peroxidase (GPx) activities) were studied in the liver and plasma. When the diet was deprived in n-3 PUFAs, ALA, (eicosanoic acid) EPA and docosahexaenoic acid (DHA) levels decreased in all lipid fractions of plasma and in red blood cell (RBC) lipids. The addition of ALA in the diet linearly improves its bioavailability and its bioconversion in EPA (R²=0.98). By providing 10 to 24% ALA in dietary lipids (LA/ALA, 1·6 and 5·5 respectively), ALA and EPA were more broadly packaged in all lipid fractions (triglyceride (TAG), cholesterol ester (CE) and free fatty acids (FFA)) of plasma from 15 to 30 days timeframe. Only 3% ALA was sufficient to promote the maximal bioconversion of ALA in DHA in phospholipid (PL) and TAG fractions. Additionally, the improvement of ALA bioconversion in EPA and DHA did not impact the oxidative stress markers and limiting lipid peroxidation. To conclude, this study demonstrated that in rat, 10% ALA in the lipid diet for 15-30 days promotes its bioavailability and its bioconversion and allowed the greatest levels in plasma and RBCs.

Acyl-CoA synthetase 6 is required for brain docosahexaenoic acid retention and neuroprotection during aging.

The omega-3 fatty acid docosahexaenoic acid (DHA) inversely relates to neurological impairments with aging; however, limited nondietary models manipulating brain DHA have hindered a direct linkage. We discovered that loss of long-chain acyl-CoA synthetase 6 in mice (Acsl6–/–) depletes brain membrane phospholipid DHA levels, independent of diet. Here, Acsl6–/– brains contained lower DHA compared with controls across the life span. The loss of DHA- and increased arachidonate-enriched phospholipids were visualized by MALDI imaging predominantly in neuron-rich regions where single-molecule RNA in situ hybridization localized Acsl6 to neurons. ACSL6 is also astrocytic; however, we found that astrocyte-specific ACSL6 depletion did not alter membrane DHA because astrocytes express a non–DHA-preferring ACSL6 variant. Across the life span, Acsl6–/– mice exhibited hyperlocomotion, impairments in working spatial memory, and increased cholesterol biosynthesis genes. Aging caused Acsl6–/– brains to decrease the expression of membrane, bioenergetic, ribosomal, and synaptic genes and increase the expression of immune response genes. With age, the Acsl6–/– cerebellum became inflamed and gliotic. Together, our findings suggest that ACSL6 promotes membrane DHA enrichment in neurons, but not in astrocytes, and is important for neuronal DHA levels across the life span. The loss of ACSL6 impacts motor function, memory, and age-related neuroinflammation, reflecting the importance of neuronal ACSL6-mediated lipid metabolism across the life span.

The role of maternal nutrition during pregnancy in the intergenerational transmission of childhood adversity

Adverse childhood experiences (ACEs) of a woman can lead to dysregulated hypothalamus-pituitary-adrenal (HPA) axis during pregnancy, which can in turn adversely affect her offspring HPA axis function. Choline and docosahexaenoic acid (DHA) are dietary factors with the potential to favorably modify the stress response system. The current study aimed to investigate whether maternal choline intake and DHA status moderate the effects of maternal ACEs exposure on maternal and infant HPA axes function. Participants were a sub-sample of the prospective longitudinal Alberta Pregnancy Outcomes and Nutrition (APrON) study consisting of 340 mothers and 238 infants. We collected data on maternal ACEs, maternal choline intake (24-hour dietary recall) and serum phospholipid DHA concentrations (at each trimester). Women self-collected saliva samples on two consecutive days (at waking, +30 min, 1100 h, and 2100 h) in each trimester to calculate the cortisol awakening response (CAR) and total daytime cortisol. Infants’ salivary cortisol was measured before and after (20, and 40 min) exposure to a blood draw stressor 3 months postpartum. During pregnancy, choline intake moderated (reduced) the association between maternal ACEs and CAR (β = −0.003; 95% CI −0.006, −0.003), but not total daytime cortisol. DHA status did not moderate the association between ACEs and CAR or total daytime cortisol. Choline intake also moderated (reduced) the association between maternal CAR and infant cortisol during a stress task (β = −0.0001; 95% CI −0.0002, −0.00003). Maternal DHA status revealed no modifying effects on these associations. Our findings suggest that maternal choline intake, but not DHA status, can buffer the associations between ACEs and maternal HPA axis, as well as maternal and infant HPA axes function.

Acyl‐CoA synthetase 6 is required for brain docosahexaenoic acid retention and neuroprotection during aging

The omega-3 fatty acid docosahexaenoic acid (DHA) inversely relates to neurological impairments with aging. However, limited non-dietary in vivo models specifically depleting brain DHA have limited direct linkage of DHA to neurological aging processes. We discovered that loss of long-chain acyl-CoA synthetase 6 (ACSL6) depletes brain membrane phospholipid DHA levels. Here, the effects of membrane phospholipid DHA depletion on behavioral and neurological outcomes across the natural progression of aging in control and Acsl6 knockout mice (Acsl6-/-) were determined. Across the lifespan, Acsl6-/- brains contained lower DHA compared to controls. The loss of DHA-enriched and increased arachidonic acid-enriched phospholipids was visualized by MALDI imaging, predominantly in neuronal rich regions where robust Acsl6 gene expression localized by smFISH to neurons across the brain, including pyramidal, Purkinje, and within the cerebellar granular layer. ACSL6 was also found in astrocytes; however, astrocyte-specific loss of ACSL6 did not regulate membrane DHA, a phenomenon attributed to astrocyte-specific expression of alternative-exon ACSL6 variants that do not prefer DHA as substrate. Total ACSL6 knockout mice exhibited hyperlocomotion across the lifespan, early-onset impairments in working spatial memory, and increased expression of cholesterol biosynthesis genes. In response to aging, cerebellar neuroinflammation and gliosis developed. Neuroinflammation was not accompanied by major alterations of lipid mediators but was preceded by decreased expression of synaptic proteins. Together our findings suggest that ACSL6 is enriched in neurons to promote membrane DHA enrichment, is important for brain DHA levels across the lifespan, protects against disordered motor function, memory, and age-related neuroinflammation reflecting the importance of DHA, and its metabolism by ACSL6, early in life and in age-related neuroprotection.

Effect of Enteral Lipid Supplement on Severe Retinopathy of Prematurity

Lack of arachidonic acid (AA) and docosahexaenoic acid (DHA) after extremely preterm birth may contribute to preterm morbidity, including retinopathy of prematurity (ROP). To determine whether enteral supplementation with fatty acids from birth to 40 weeks' postmenstrual age reduces ROP in extremely preterm infants. The Mega Donna Mega trial, a randomized clinical trial, was a multicenter study performed at 3 university hospitals in Sweden from December 15, 2016, to December 15, 2019. The screening pediatric ophthalmologists were masked to patient groupings. A total of 209 infants born at less than 28 weeks' gestation were tested for eligibility, and 206 infants were included. Efficacy analyses were performed on as-randomized groups on the intention-to-treat population and on the per-protocol population using as-treated groups. Statistical analyses were performed from February to April 2020. Infants received either supplementation with an enteral oil providing AA (100 mg/kg/d) and DHA (50 mg/kg/d) (AA:DHA group) or no supplementation within 3 days after birth until 40 weeks' postmenstrual age. The primary outcome was severe ROP (stage 3 and/or type 1). The secondary outcomes were AA and DHA serum levels and rates of other complications of preterm birth. A total of 101 infants (58 boys [57.4%]; mean [SD] gestational age, 25.5 [1.5] weeks) were included in the AA:DHA group, and 105 infants (59 boys [56.2%]; mean [SD] gestational age, 25.5 [1.4] weeks) were included in the control group. Treatment with AA and DHA reduced severe ROP compared with the standard of care (16 of 101 [15.8%] in the AA:DHA group vs 35 of 105 [33.3%] in the control group; adjusted relative risk, 0.50 [95% CI, 0.28-0.91]; P = .02). The AA:DHA group had significantly higher fractions of AA and DHA in serum phospholipids compared with controls (overall mean difference in AA:DHA group, 0.82 mol% [95% CI, 0.46-1.18 mol%]; P < .001; overall mean difference in control group, 0.13 mol% [95% CI, 0.01-0.24 mol%]; P = .03). There were no significant differences between the AA:DHA group and the control group in the rates of bronchopulmonary dysplasia (48 of 101 [47.5%] vs 48 of 105 [45.7%]) and of any grade of intraventricular hemorrhage (43 of 101 [42.6%] vs 42 of 105 [40.0%]). In the AA:DHA group and control group, respectively, sepsis occurred in 42 of 101 infants (41.6%) and 53 of 105 infants (50.5%), serious adverse events occurred in 26 of 101 infants (25.7%) and 26 of 105 infants (24.8%), and 16 of 101 infants (15.8%) and 13 of 106 infants (12.3%) died. This study found that, compared with standard of care, enteral AA:DHA supplementation lowered the risk of severe ROP by 50% and showed overall higher serum levels of both AA and DHA. Enteral lipid supplementation with AA:DHA is a novel preventive strategy to decrease severe ROP in extremely preterm infants. ClinicalTrials.gov Identifier: NCT03201588.

Effects of Varying Dietary Docosahexaenoic, Eicosapentaenoic, Linoleic, and α-Linolenic Acid Levels on Fatty Acid Composition of Phospholipids and Neutral Lipids in the Liver of Atlantic Salmon, Salmo salar

Fish oil, the most abundant natural source of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), is a limited resource; however, terrestrial oils are used as an alternative in fish nutrition. The liver of Atlantic salmon is able to synthesize these two long-chain n-3 polyunsaturated fatty acids (n-3LC-PUFAs) from α-linolenic acid (ALA), but the dietary levels of EPA + DHA and the ratios of linoleic acid (LNA) to ALA may affect its abilities. Feeding Atlantic salmon four experimental diets containing EPA + DHA at 0.3 and 1.0% of dietary levels accompanied with high and low LNA/ALA ratios showed that low LNA/ALA ratios increased the proportions of EPA + DHA in phospholipids (PLs) and neutral lipids (NLs). The pattern of PL-to-NL ratios of n-3 LC-PUFA proportions matched the saw tooth pattern of LNA/ALA ratios in diets. Overall, when fish oil is removed from salmon diets, the dietary LNA/ALA ratio must be reduced to stimulate biosynthesis of n-3 LC-PUFAs in the liver.

Advances in exogenous docosahexaenoic acid-containing phospholipids: Sources, positional isomerism, biological activities, and advantages.

In recent years, docosahexaenoic acid-containing phospholipids (DHA-PLs) have attracted much attention because of theirs unique health benefits. Compared with other forms of docosahexaenoic acid (DHA), DHA-PLs possess superior biological effects (e.g., anticancer, lipid metabolism regulation, visual development, and brain and nervous system biochemical reactions), more intricate metabolism mechanisms, and a stronger attraction to consumer. The production of DHA-PLs is hampered by several challenges associated with the limited content of DHA-PLs in natural sources, incomplete utilization of by-products, few microorganisms for DHA-PLs production, high cost, and complex process of artificial preparation of DHA-PLs. In this article, the sources, biological activities, and commercial applications of DHA-PLs were summarized, with intensive discussions on advantages of DHA-PLs over DHA, isomerism of DHA in phospholipids (PLs), and brain health. The excellent biological characteristics of DHA-PLs are primarily concerned with DHA and PLs. The metabolic fate of different DHA-PLs varies from the position of DHA in PLs to polar groups in DHA-PLs. Overall, well understanding of DHA-PLs about their sources and characteristics is critical to accelerate the production of DHA-PLs, economically enhance the value of DHA-PLs, and improve the applicability of DHA-PLs and the acceptance of consumers.

Enriching ISA brown and Shaver white breeder diets with sources of n−3 polyunsaturated fatty acids increased embryonic utilization of docosahexaenoic acid

There is limited information on feeding egg-type chick breeders n−3 polyunsaturated fatty acids (PUFA) and its impact on hatching egg quality and embryonic fatty acid (FA) utilization. We investigated the effects of feeding brown and white egg-type chick breeders diets containing sources of n−3 PUFA on egg composition, apparent embryonic FA utilization, and intestinal FA transporter in hatchlings. Twenty-six-week-old ISA brown and Shaver white breeders were fed either 1) control (CON); 2) CON + 1% of microalgae (DMA, Aurantiochytrium limacinum) fermentation product, as a source of docosahexaenoic acid (DHA); or 3) CON + 2.60% of coextruded full-fat flaxseed and pulse mixture (FFF, 1:1 wt/wt) as a source of α-linolenic acid (ALA). Test diets had similar total n−3 and n−6:n−3 ratio. Eggs were hatched, and residual yolk (RY) samples taken for FA analyses. Apparent embryonic FA utilization was calculated by subtracting concentration of FA in RY from concentration of FA in yolk before incubation. There was an interaction between strains and diets (P < 0.05) on DHA in phospholipid and triglyceride fractions of yolk. Both n−3 PUFA sources increased DHA to a greater extent in Shaver white than in ISA brown. The interactive effect of strains and diets (P = 0.019) on embryonic utilization of ALA was such that DMA and FFF reduced ALA utilization, and this pattern was more prevalent in Shaver white birds than in ISA brown birds. There was no interaction between strains and diets on DHA utilization (P > 0.05). Embryos from hens fed n−3 PUFA sources used less total FA in phospholipid fraction (P < 0.001), and they preferentially used more DHA than CON embryos. Shaver white embryos used more (P < 0.05) ALA and DHA than ISA brown embryos. Although data suggested Shaver white had higher propensity of depositing DHA than ISA brown, irrespective of strain, feeding n−3 PUFA modified embryonic pattern of FA utilization toward utilization of DHA.

Different metabolism of EPA, DPA and DHA in humans: A double-blind cross-over study

This study aimed to compare eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) incorporated into red blood cells (RBC) phospholipids (PL), plasma PL, plasma triglyceride (TAG), and plasma cholesteryl ester (CE) fractions, and the metabolomics profiles in a double-blind cross-over study. Twelve female healthy subjects randomly consumed 1 g per day for 6 days of pure EPA, DPA, or DHA. The placebo treatment was olive oil. The fasting venous blood was taken at days 0, 3 and 6, and the RBC PL and plasma lipid fractions were separated for fatty acid determination using thin layer chromatography followed by gas chromatography. Plasma metabolites were analyzed by UHPLC-Q-Exactive Orbitrap/MS. Supplemental EPA significantly increased the concentrations of EPA in RBC PL (days 3 and 6). For subjects consuming the DPA supplement, the concentrations of both DPA and EPA were significantly increased in RBC PL over a 6-day period, respectively. For plasma PL fraction, EPA and DPA supplementation significantly increased the concentrations of EPA and DPA at both days 3 and 6, respectively. Supplemental DHA significantly increased the concentrations of DHA in plasma PL at day 6. For plasma TAG fraction, supplementation with EPA and DPA significantly increased the concentrations of EPA and DPA at both days 3 and 6, respectively. After DHA supplementation, significant increases in the concentrations of DHA were found relative to baseline at both days 3 and 6. For plasma CE fraction, EPA supplementation significantly increased the concentrations of EPA (days 3 and 6) and DPA (days 6), respectively. Supplemental DPA significantly increased the concentrations of EPA at day 6. Meanwhile, the concentrations of DHA were significantly increased over a 6-day period of intervention after subjects consuming the DHA supplements. There were a total of 922 plasma metabolites identified using metabolomics analyses. Supplementation with DPA and DHA significantly increased the levels of sphingosine 1-phosphate (P for DPA = 0.025, P for DHA = 0.029) and 15-deoxy-Δ12,14-prostaglandin A1 (P for DPA = 0.034; P for DHA = 0.021) in comparison with olive oil group. Additionally, supplementation with EPA (P = 0.007) and DHA (P = 0.005) significantly reduced the levels of linoleyl carnitine, compared with olive oil group. This study shows that DPA might act as a reservoir of n-3 LCP incorporated into blood lipid fractions, metabolized into DHA, and retro-converted back to EPA. Metabolomics analyses indicate that supplemental EPA, DPA and DHA have shared and differentiated metabolites. The differences of these metabolic biomarkers should be investigated in additional studies.

Lipid Distribution Pattern and Transcriptomic Insights Revealed the Potential Mechanism of Docosahexaenoic Acid Traffics in Schizochytrium sp. A-2.

Schizochytrium sp. A-2 is a heterotrophic marine fungus used for the commercial production of docosahexaenoic acid (DHA). However, the pattern of the distribution of DHA and how DHA is channeled into phospholipid (PL) and triacylglycerol (TAG) are unknown. In this study, we systematically analyzed the distribution of DHA in TAG and PL during the growth of the cell. The migration of DHA from PL to TAG was presumed during the fermentation cycle. DHA and docosapentaenoic acid were accumulated in both TAG and phosphatidylcholine (PC), whereas eicosapentaenoic acid was mainly deposited in PC. RNA seq revealed that malic enzyme may provide lipogenic NADPH. In addition, long-chain acyl-CoA synthase and acyl-CoA:lysophosphatidylcholine acyltransferase may participate in the accumulation of DHA in PL. No phosphatidylcholine:diacylglycerol cholinephosphotransferase was identified from the genome sequence. In contrast, phospholipid:diacylglycerol acyltransferase-mediated acyl-CoA-independent TAG synthesis pathway and phospholipase C may contribute to the channeling of DHA from PC to TAG.